Socrates & Plato



Quotes & Notes

Socrates v. Sophism & Skepticism

"Crito we owe a cock to Aesculapius.  Pay it and do not neglect it."

There is objective knowledge

of truth

and value

we can arrive at  dialectically, by reasoning together

like legal reasoning -- thesis v. antithesis -- but

the object is to discover the truth

not winning the argument

and not just agreeing either!

Three innovations

Universal definitions

Inductive dialectical method

Ethical emphasis

Ironic practice

Virtue = knowledge: denial of akrasia

1.       “A man who really fights for the right, if he is to preserve his life, even for a little while, must be a private citizen, not a public man."

2.       “The unexamined life is not worth living.”

3.       “And is not this the most reprehensible form of ignorance, thinking one knows what one does not know."

4.       "[A]nd if . . . I am wiser in anything, it would be in this, that not knowing . . . I do not think I know."

5.       “When people make a wrong choice of pleasures and pains – that is, of good and evil – the cause of their mistake is lack of knowledge.  … So that is what 'being mastered by pleasure' really is--ignorance, and most serious ignorance.”(357d-e).



Received issues

appearance v. reality

one v. many

problem of change

possibility of knowledge

How is change possible?

Cases other than absolute creation or destruction.

assume variation (i.e., change)

of something that remains one and the same thing (i.e., unchanged).

Two realms

sensible things: changing “visible” reality.

unchanging Forms that things can take. 

1.       "[I] remind you of the distinction we drew . . . between the multiplicity of things that we call good or beautiful or whatever it may be and, on the other hand, Goodness itself or Beauty itself and so on.  Corresponding to each of these sets of many things, we postulate a single Form or real essence, as we call it."



Plato's "Ideas" are Objects of Knowledge: e.g. the idea that we share of The Dog, The Tree, etc., not private mental events -- mere thoughts

The Forms


Individuals (e.g., LH) temporarily instance universals (e.g., standing, humanity, being shod, being fair).


LH is a fair grader just as  objectively and absolutely true (or not, as the case may me) as LH has a fair complexion.


LH lives: true 1949-??

Humans are living things: true always.

General character: unchanging natures that individual things temporarily "participate in" or "resemble": immaterial, insensible, unchanging.

Mathematical Application

Mathematics embodies knowledge & makes discoveries.

That are not about sensible things.

Ethical Application: There are objective values.

Scientific Laws: always & everywhere true

Beliefs are  based on perception and are unreliable due to the vagaries of sensible reality.  Harry is a bachelor.  The light is red. 

Knowledge of unchanging truths is secure: Bachelors are unmarried.  What's red is not green.

1.       "[Geometers] are not reasoning, for example, about this particular square and diagonal which they have drawn, but about the Square and the Diagonal; and so in all cases."

2.       "[T]he many things we say can be seen, but are not objects of rational thought; whereas the forms are objects of thought, but invisible."



Two minds with a single thought


communication (c.f. Gorgias)

Universals v. Prototypes

Articulating the real essence -- the Form -- defines what it is to be a thing of that type.

The Divided










IDEAL REALM of FORMS: objects of thought

Higher Forms: Goodness, Beauty, Etc.

Objects of Intelligence (intellectual insight): Pure Reason: Universals

Lower Forms: Numbers and Geometrical

Objects of hypothetical thought: Understanding

Abstract Particulars

PHYSICAL WORLD: sensible objects; concrete particulars

Physical Things: Bill, MJ; rocking chair, folding chair.

Phantasmagia: shadows, reflections, images.

1.       "Take a divided line divided into two equal parts, one to represent the visible order, the other the invisible; and divide each part again in the same proportion, symbolizing degrees of comparative clarity and obscurity."

2.       "And now you may take, as corresponding to the four sections, these four states of mind: intelligence for the highest, thinking for the second, belief for the third, and for the last imagining.  These you may arrange as the terms in a proportion, assigning to each a degree of clearness and certainty corresponding to the measure in which their objects possess truth and reality."